Valve mechanism for player-plano actions



March 11 1924. 1,486,185

A. G. GULBRANSEN I, VALVE MECHANISM FOR PLAYER PIANO ACTIONS 0-7 -l I ll l I l 1 IL L Patented Mar. 11, 1924.

UNITED STATES PATENT OFFICE.

AXEL G. GULBRANSEN, OF CHICAGO, ILLINOIS, .ASSIGNOR TO GULBRANSEN- DICKINSON (30., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

VALVE MECHANISM FOR PLAYER-PIANO ACTIONS.

Application filed October 25, 1918.

To all whom it may concern:

Be it known that I, Axni. G. GULBRAN- SEN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Valve Mechanism for Player-Piano Actions, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates generally t0 player pianos or instruments of like character and has special reference to pneumatic valve i'nechanism for such instruments.

The successful operation of a player piano, as judged by the user, depends largely upon two important features, namely, ease of operation and accuracy, uniformity and quickness of response of the pneumatic action to the corresponding note perforation of the music roll.

As a certain amount of power is required to sound each note, the aggregate amount of power required to operate the instrument is readily seen to depend upon the number and length of notes struck. This is really very little, but the power which the operator must furnish at the pedals is in many in struments so great as to spoil the pleasure of playing the instrument.

The amount of power applied at the pedals in excess of that actually expended in the playing mechanism is lost either in. as leakage of air at the valves or other parts of the system, or in performing unnecessary work due to faulty design or operation.

As there are eighty eight notes in a standard instrument and as each note must have its own valve and pneumatic it is at once evident that the design and operation of the \ulri-s and pneunutics is of the greatest importance in producing a good instrument. If the valves are leaky or take more power than is necessary, the instrument plays hard. If the valves and pncumatics waste power due to poor design or any other cause, the same thing is true.

If on the other hand, the valves have in sufficient power or do not respond instantly the instrument operates feebly or slowly and will fail to make quick repetition.

I have found that the speed at which the valves must operate to give the desired quickness of playing is so great that a rigid Serial No. 259,614.

valve tends to rebound and is noisy. I have conceived the idea of breaking the moving parts of the valve as a whole into a plurality of rigid parts connected by yielding flexible parts. Thereby I gain a double advantage. The impact of the valves is taken up quietly and instantly, preventing noise and avoiding leakage and in addition the flexible yielding connection serves as a universal joint of limited motion and causes the valve to seat invariably and instantly. This latter feature overcomes leakage and permits the instrument to operate with surprising speed and uniformity, even in spite of the small inaccuracies in the manufacture and assembly of the parts incidental to large scale production.

To insure accurate and responsive valve seating I mount the valve on its stem by means of a reduced flexible pad.

To increase the speed and power of the valve operating diaphragm, I have provided a disc working in connection with the usual diaphragm to permit the pressure of the air upon the diaphragm to be applied in stantly and without developing detrimental local stresses in the diaphragm. I have connected this disc to the diaphragm by a yieldable and flexible connecting member which prevents any sidestrain or localized concentration of pressure upon the diaphragm. Long life of the diaphragm is thus assured. The disc in turn is connected to the valve stem by a yieldable and flexible connecting member so that there are yieldable and flexible members between the various elements of the valve and its operating mechanisms and the entire mechanism is light and strong. I preferably employ small pads of a soft fibrous material such as felt to form the flexible and yieldable connecting mem' bers. Other means, such for instance as a spring, may be employed.

I wish to call attention to the fact that the two features of flexibility and yieldability are separable and either one alone may be used to advantage, although I find it convenient in the preferred form of my invention to secure both functions in one structure.

Other advantages and features of my invention will be apparent from a detailed description of the preferred embodiment of the invention.-

My invention will be more readily understood by reference to said drawings illustrating a preferred embodiment thereof, and in which:

Figure 1 is afragmentary view in elevation, of a piano player pneumatic action shoivn partly in section to better illustrate the invention;

Figure 2 is an enlarged fragmentary sectional view of the valve and its co-operating parts; and

Figure 3 is a detail it'ragmentary horizontal section on the line 33 of Figure 2.

In said drawings 1 is a channel board similar to that used in many such piano actions. enter ding horizontally the le' th or the piano he heard and supported in ends upon suitahle brackets or other supports. Upon the rear is mounted a bank of pneumatics 2 arranged in three horizontal rows and in vertical staggered relation and connected by individual abstracts 3 to operating lovers 4 which engage suitable parts of a piano action to produce playing.

The pneumatics 2 are of usual or any preferred construction, consisting of an upper fixed leaf 5 and a lower hinged leal': G the two leaves being connected by collapsiole fabric '7 to form a bellows. Each pneumatic is secured to the under side of a block 8 which is glued or otherwise fastened to the rear face of the channel heart l and which block 8 contains the valve mechanism for the pneumatic. The hinged board 6 of the bellows is hinged adjacent to the channel hoard and its opposite end extended beyond the bellows for connection to the up per end of the corresponding abstract by a connection permitting a limited rocking motion.

The blocks controls the each contain a valve 9 which ction t tie bellows. The valve 9 i" controlled by the note perforations in the note sheet through the o t'acker bar opening: to admit suction to or shut suction of? t the corresponding pneumatic. The valve 9 (lat disc head 10 and a groove! 1 ll, the head operati g: Within 3 to control atmospheric and sentering same. A assageuct the chamber 12 with the i pneumatic 2. lflorniall v, the interior 0 pneumatic is connected to the a'tznos through the port 1% tormthe o seat 15 which closes tchamber 12. This plia a pluralnr of discs or board. fibre or the like. i prefera vide rounded edges on the valve sea at the ends of the port 14. The va 10 when in the normally inactive pos seats on av valve seat 17 and thus (:01 trols communication between the valve chamher 12 and the exhaust passageiva; The

- Xhaust channel l end air exhaust c 1 constitutin j mechanism. Th 18 is normally 0 u: .tethe valve head upon the up sum ion bein therco i .i.

o 2? and 23, into t phrae in chamber or these pus: i O

:er board the under one c r val lUT;

n t atmooh 1o 13 Will ected fro-:1 nected to t 11.) quen l? he lit! nevved or c1 lerent sized 1 i obtain the re iret rapidity of action. it 3' obvious that when the tracker opening is again closed, the passage 23 with its connections and the lower part of the diaphragm chamber are exhausted through the bleeder opening, and in consequence the diaphragm is rendered inactive. The valve 9 drops, opening the port l t and closing the port 10, thus placing the interior of the pneumatic in communication with the atmosphere and permitting same to open or expand.

Referring now particularly to the valve 9 and its (to-operating devices,I have provided a valve which will accurately and tightly seat in both directions whether the two seats are absolutely parallel or not, and whether or not the contacting surfaces of the valve head and seats are accurately at right angles to the bore in which the valve moves. For this purpose I connect the head to the valve stem 11 by means of a yielding joint member 33 which can be a small piece of felt, relatively soft leather, or other suitable yielding material. I connect the head and the stem to the yielding connector 33 by glueing or otherwise permanently joining them. This provides a universal joint of limited motion. I build up the valve head of a rigid middle disc 34, preferably wood, faced on the top and bottom with thin leather or some other similar relatively soft material As mentioned hereinbefore, the seat 15 is yielding. I preferably build it up of a number of layers of cardboard, leather, or some other suitable material. I preferably make the stem 11 smaller than the bore 36 in which it is contained, so that the stem will move freely therein. It might occur that if the head and stem were rigidly connected, the stem would prevent the accurate seating of the valve. By means of my yielding connection, which is aptly described as a universal joint, between these parts, the head 10 is free to be tightly seated upon the upper seat 14: or the lower seat 17 regardless of the relative alignment of the head and stem 11. The seat 17 is formed of a small metal thimble 37 which is flared or coned enough to provide a tight fit when the same is forced or driven into place in the block 8. The thimble 37 is seated in the bore 36 with its upper end projecting slightly above the lower wal 38 of the valve chamber 12. The leather s1 ces on the valve head not only assist in the tight closing of the valve, but also in providing a quiet action of the valve.

The diaphragm which is preferably made of thin leather is of large area' relatively to the area of the valve stem, and for the purpose of enlarging the area of contact between these two parts I provide an en lm'gement non-rigidly associated with the lower end of the stem 11, in the form of a disk 39 of cardboard, wood or the like, generally termed. a pressure distributing member. I connect to the lower end of the stem 11 in central relation thereto by means of a yielding pad or connector 40 similar to the connector at the upper end of the valve. I preferably make the disk 39 of pasteboard, which is light and relatively rigid, and I prefer to make the disk considerably larger than the stem 11 and smaller than the diaphragm, so that the disk is arranged to bear upon the diaphragm about midway between the pad 40 and the edge of the diaphragm.

To further cushion the diaphragm on the valve I provide a flexible pad 41 centrally below the disk 89 and preferably, but not necessarily, secured thereto. I make this pad 4:1. thick enough to fill in between the curvature ofthe diaphragm when inactive and the disk 39 so that, as best illustrated in Figure 2, the diapln'agm, when inactive, normally touches the outer edge of the disk 39. Thus there are flexible or universal connections between all rigid parts of the valve as a whole, and between the diaphragm and the rigid disk member 39.

The yielding pad 40 between the disk 39 and the valve 11 serves as a universal joint to permit the disk to accommodate itself to the diaphragm without producing any undue or detrimental friction upon the valve; in other words, if the diaphragm should not rise uniformly the disk 39 can yield relatively to the valve to accommodate itself to such action, thus lessening any tendency to cocking or tilting the valve. The disc with its pads forms a distributing member connected by a universal joint of limited motion between the diaphragm and the valve stem.

By means of the enlarged lower end of the stem which the disk provides, I secure a quicker and more positive lifting of the valve, when the diaphragm operates, due to the greater area over which pressure is applied to the valve. Also the disk 39 and the pressure pad -11 present a greater area of contact between the valve and diaphragm which prevents undue or sharp flexing of the diapluragm.

I claim:

1. A valve for a player piano action, comprising a valve head and a stem and a pad of soft fibrous material glued to the head and to the end of the stem and forming the sole connection between these two parts, said pad having a cross-sectional area less than that of the stem.

2. In a valve mechanism of the kind described, valve, a relatively thin flexible diaphragm for moving the valve, a substantially rigid disk carried by the valve for contact with the diaphragm, and a yielding pad interposed between the disk and the dia phragm, the diaphragm normally contacting Iit) with the dish adjacer its periph with said wherebv th haph i ex reme tieI-Iing a any point. valve in ehanism of the 1nd dea rchn ivelv thin -.ible diaphrai JeOJ a *alve ha 'ing a stem arrz, ative v to he 1 1 i i said ii -tan er o aniosohere. an n,

pneuniat c cured t passes: number 3 pneuina l ii lOfi' \Y rorming '1 low valve so way conentrrc with sea passageway below the di i tracker opening, a flu mounted in tie vtlve chamber a d meter sunstantialiv th he vertical 1 assae'ewav guid a pad of soft ti irous mater'i t e oottom of the valve oisl: ane 1e ;t he stem to permit movement the (llSK into 1 ent plane having: a

I] V recess in the top a valve chain r, valve seait men l ,ving its edges secuset o recess, a passageway exten,

i o atmosnher an member t pneumatic its curen to the lo "31' a passagewav from the valve chamber to sta i uarv ho IQ SG- valve block,

an intermediate porn tracker board opening, a flat non rigid disc valve mounted in the valve chamber, a stem of a diameter substantially the same size as the vertical passageway guided therein, a

disc resting upon the diaphragm, a pad of soft fibrous material glued to the bottom of tile sten and to the top of the disc.

6. In a valve mechanism, a flexible diaphragm, valve stem, a valve, a terrible cmnprcssible 1 ad of a cross section less than that of said stein glued between said valve and the end of said stem and forming the sole connection therebetween, a flexible compressible pad at the other end oi said stem, and a dis o hen said flexible diaphrag n and larger than he crc ss scction of I i i i said stein operativelv (ilF-YPOSH betwe n id ble pad in combination, a

Jon. and a tlexmle pad between the two forming a unive l connection, said stein being of greater r: (rial dimensions than ilve cor ipris aid pad throughout predctrinined portions of its periphery and of less dimensions than throughout the remaining portions. a valve mechanism of the kind deicribed, a valve having a head and a guide flexible diaphragm for lifting the means carried by the stem and resting iaphrags'n tor increasing the effective 1 ea of contact between the stem and the diaphragm, and a pad of yieldable material interposed between said means and the stem to positively connect the same.

9. In combination, a block having a 'alve chamber and flexible disk of laminated librous material secured over the valve chainher to form a valve seat, a valve having univ rsal movement and adapted to engage said seat, said disc being perforated to provide a passageway.

10. In combination, a diaphragm, a valve stem, a pressure distributor, the distributor contacting with the diaphragm, a pad oi soft fibrous mate ial lying between the central portion of the distributor and the diaphragm, and pad of soft fibrous material secured between the end of the va ve stem and the adjacent face of the distributor and forming the sole connection therebetwcen.

11. A valve comprising, in combination, a head, a stem, and a flexible pad between the two forming a universal connection, said stem being of greater radial dimensions than said pad throughout predetermined sym metrically disposed portions of its periphery and of less dimensions than said pad throughout the remaining portions.

12. A valve for a player piano action, comprising i valve head, a stem, and a pad of soft fibrous material secured to the head and to the end of the stem and forming the sole connection between these two parts, said pad having radial dimensions less than those of the stem, but a cross sectional area greater than that of the stem.

13. A valve comprising, in combination, a head, a stem, and a resilient pad between the same, said pad making contact on one side over a circular area and on the other side over a smaller crossshapcd area.

14. A. valve comprising, in combination, a head, a stem, and a resilient pad between the same, said pad making contact on one side over a circular area and on the other side over a smaller cross-shaped area having arms of the same radial dimensions as said circular area.

15. A valve comprising, in combination, a stem of cross-shaped cross section, a circular disk adjacent one end of said stem, and a resilient pad having contact on one side with said disk and on a portion of the other side with a portion of theend of said stem.

16. A valve comprising, in combination, a stem, an actuating diaphragm, and a contact disk of radial dimensions intermediate between those of the stem and diaphragm,

said disk being flexibly attached to said stem.

, 17. A valve comprising, in combination, a stem, a head, said stem and head having their opposed surfaces composed of different materials having diiierent rigidity, and a flexible pad interposed between said surfaces, the contact surface between the pad and the material of greater rigidity being less than the contact surface between the pad and the material of less rigidity.

18. In a valve mechanism, in combination, a valve head, a valve stem, a flexible pad glued between said head and stem and constituting the sole connection between them, and means for actuating said stem, said pad connection being capable of carrying tension to support the stem suspended from the head.

In Witness whereof I hereunto subscribe my name this 22nd day of October, A. D.

AXEL G. GULBRANSEN. 

